1 - Yes its slow, but has a massive library, I don't actually use it much apart from to sync, it downloads new podcasts without me doing anything so I barely have any trouble with it.
2 - Yep, it's damn awful
3 - I would like a sticky note option, it could be nicely implemented (ie it wasn't in any fixed position on the home screen so could be moved round over your icons like a proper post it)
4 - Multitasking in that you can play music in the background, you can't switch between note/safari without closing one of them. They do pop back up where you left off but (IMO) it's not 'proper' multitasking.
5 - You can BT photos from one iPhone to another using an app, but that's it so far! Radio - guess that's a personal thing as I never really used one.